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Page 19 <br /> <br /> <br />effectively treat stormwater runoff. Site design should address open space protection, impervious <br />cover minimization, and runoff distribution and minimization, and runoff utilization” (2). The <br />forthcoming stormwater management plan will be in accordance with the City’s regulations <br />identified in the Chapter 30 and generally summarized below: <br /> Post-construction runoff volume shall be retained on site for 1.1 inches of runoff from <br />all impervious surfaces on the site. <br /> Treatment must achieve an 80% removal of suspended solids <br /> Stormwater shall be treated to remove 60% of the post-development phosphorous <br />load on an annual basis before discharging to natural water bodies. <br /> For post-construction rate control modeling a minimum curve number of 84 shall be <br />used on all disturbed/graded soil areas, due to soil compaction impacts. <br /> Projects shall have no increase in runoff from the predevelopment peak runoff rates <br />for the 2-year, 10-year, and 100-year, 24-hour storm events. <br /> All stormwater pipe sizing must be sized according to the City of Elk River <br />Engineering Design Standards Manual. <br /> Discharges from new construction sites must have a stable outlet capable of carrying <br />designed flow at non-erosive velocity. <br /> <br />Conditions for stabilizing disturbed soils, establishing buffers/setbacks, and other specific permit <br />requirements will be followed. In accordance with Chapter 30, section 30-1852 of the City code, <br />25-foot buffer strips will be established from the delineated wetland boundary and the ordinary <br />high-water level of stormwater ponds (2). Likewise, a minimum 20-foot setback from the wetland <br />buffer strip will also be established (2). <br /> <br />The site will be graded to promote surface water drainage and to maximize the runoff that is <br />treated before leaving the site. Stormwater from the residential and commercial development will <br />be directed to permanent stormwater features (infiltration basins and stormwater ponds). The <br />BMPs will control the rate of stormwater runoff discharges to comply with local and state <br />requirements. <br /> <br />v) Water appropriation – Describe if the project proposes to appropriate surface or <br />groundwater (including dewatering). Describe the source, quantity, duration, use and <br />purpose of the water use and if a DNR water appropriation permit is required. <br />Describe any well abandonment. If connecting to an existing municipal water supply, <br />identify the wells to be used as a water source and any effects on, or required <br />expansion of, municipal water infrastructure. Discuss environmental effects from <br />water appropriation, including an assessment of the water resources available for <br />appropriation. Discuss how the proposed water use is resilient in the event of changes <br />in total precipitation, large precipitation events, drought, increased temperatures, <br />variable surface water flows and elevations, and longer growing seasons. Identify any <br />measures to avoid, minimize, or mitigate environmental effects from the water <br />appropriation. Describe contingency plans should the appropriation volume increase <br />beyond infrastructure capacity or water supply for the project diminish in quantity or <br />quality, such as reuse of water, connections with another water source, or emergency <br />connections.